Proceed with caution
Many answers here have said "sure, go ahead and say something, just don't be judgey". I want to emphasize that anything you say could be interpreted as being judgmental even if it's not meant that way. Consider, for one thing, that some fraction of the colleagues may feel that they are being "edgy" or "transgressive" in some sense with this behavior, while internally they know that, say, their mother would really be disappointed to hear how they talk at work.
Time/Coping skills approach
Our reaction to language is almost completely the result of cultural conditioning. There is not a remotely logical argument that there is something inherently morally wrong about, say, referring to feces with a short word instead of a long one. Speaking of short words, 'poop' is also short but considered comical rather than crude. Why is that? Think about why you react the way you do to one word that means exactly the same thing as another. This is the first step in addressing the idea logically rather than culturally/emotionally.
I was raised in a very conservative, religious household and learned to think of using vulgar language as a sin. I reacted strongly (if only internally) to "unacceptable language" and probably judged people for using it (even if you try not to, it's really hard to not think less of someone for doing something you have been taught to think of as wrong).
One day a friend of mine was talking about the origins of "bad words" [n.b. much of what follows is specific to English and some to US English and culture] and mentioned that they were rooted in the Norman (French) invasion of England. It was the lower classes who continued to use the Old English words for things. As this Quora answer explains:
Linguistic: Blame the French. In English, the word “shit” is a very
old one, and it essentially comes right out of Anglo-Saxon English
essentially in the same form. When the Norman French invaded in 1066,
many Anglo-Saxon words for everyday objects became associated with the
lower class — of course, as the Saxons had lost and the Normans had
won. That’s why we refer to a sheep (Saxon) when it’s in the field,
but mutton (French) when it’s on the plate: the high-class people were
the ones eating le mouton on plates while the loser Saxons were
tending the sheep in the fields.
Which brings us to shit. Almost all of the “dirty words” in English —
shit, f--k, c--t, c--k, a-- — are straight-up Old English /Anglo-Saxon
in origin and arrive into Modern English relatively unchanged. When
the Normans invaded, all of those words — which hadn’t necessarily
been considered to be swear words or foul language — now became
low-class and vulgar compared to the Latinate feces, fornicate,
vagina, penis, anus.
Bottom line (no pun intended), the word “shit” became a dirty word
because of the French.
Many of the words that we are trained to be sensitive to are simply the words that the common, out of power, conquered people used. Even the term "vulgar" originally just meant "of the masses".
For me, learning this one thing completely changed my perspective--I realized that I had been suckered into continuing a centuries-old prejudice that I did not agree with. That put the moral shoe on the other foot--my prejudice was immoral and needed to be overcome. It also put my reaction entirely in my control. And expanded my vocabulary (although I retain the benefit of the fact that I grew up not using that language, and don't slip in places where it would be culturally unacceptable to do so. Not often, anyway :D ).
My suggestion here is that your friend can change her attitude toward coarse language without compromising her values.
Another coping skill that a friend of mine from the same conservative community used was seeing the humor in interpreting all of the words literally. This can be quite funny and provide a mental release valve for the tension created by your conditioned reaction. [For example, your colleague: "Aww, f**k this stupid vpn server" you, mentally: "that seems physically impossible, and would probably end up with a visit to HR if you tried". It's silly, but that's the point--you remap the offensiveness to a humorous reaction. (To be extremely clear (as a commenter missed the 'mentally', so others may as well): internal monologue here, not intended as a verbal rejoinder.)]
One more coping skill that I have used is imagine that your colleagues are using language from another country. Even with my newfound disdain for the historical prejudice against the normal language of common people, I still notice the high instances of F-bombing in a particular podcast I listen to (Part of the Problem by Dave Smith, for the curious). Even if you don't think there's anything morally wrong with the language, it's incongruent with how most people I interact with use that particular word (i.e., only to express very extreme anger or disappointment). In my head, though, I just say "well, he's speaking New York [where Dave grew up]", and it makes more sense.
Build Relationships of Trust
This suggestion will also take time. As I said earlier, any suggestion that people change their language habits could be interpreted as being judgemental. If she is going to talk to someone, it should be a person that she has built a relationship of trust with, to the point that said person will not feel any hint of being judged when the topic is brought up.
Once that relationship has been developed present the problem as a problem with her that she wants help with. Not something that the colleagues are doing wrong--something she is struggling with due to her background and the cultural norms she grew up with. "I've tried a couple of coping mechanisms that a random guy on stack exchange said and they aren't working for me. Do you think people would be offended if asked them to curse less? I really like working here but it's just hard for me, and I don't want to bring it up because I don't want people to think I'm judging them for their language." [Mike M' commented that this might be best done outside of work, and presented the idea of flipping it around, asking "does it bother people that I don't swear a lot?" as a sort of trial balloon to see how they respond. He points out that in an out-of-work setting the environment is less adversarial and the vert fact that you are doing something outside of work is indicative of an actual interpersonal relationship.]
I would only use this as a last resort, though. It's a general principle in life that the person you have the most control over is yourself, and it's very empowering when your realize that your reactions can be under your control rather than just accepting the natural results of human behavior and cultural conditioning as an unchangeable fact.
