Your best source of information is your HR Department
In order to decide upon a framework, or even to build your own, you need to ask several questions about your past job vacancies.
What is the application rate of different demographics? If your application pool is largely a monoculture, look into why that is. Are you advertising in places where people of other demographics look? Are you approaching them on LinkedIn?
What motivates the people of the demographics you want to attract? If you don't know this, you need to ask this question in interviews.
Are the people of other demographics being offered roles? If not, why not? And if they are, but are turning them down, why is that?
Why do the existing people of the demographics you want to attract leave your company? Bear in mind if your company has serious culture issues, you may not get honest answers if you ask outright. Look for patterns that may indicate problems (e.g: there's an unexplained exodus or collections of negative feedback from a given department)
Once you have these answers, you'll have something that you can make tangible diversity goals and frameworks out of.