Some programs require you to submit a diversity statement as part of the application package. It is important to understand what each of the programs want here. For the schools I applied to, this statement asked to me talk about what I did in my life to promote diversity; not how admitting me would increase diversity in their program. However, some programs also do ask for the latter. Hence, please read their rubric carefully before starting to write this.  

A statement I used can be found here. (I am keeping this restricted for now but do request access by stating why you need this; not many schools ask for this)

A guide on how to write a good diversity statement can be found here.