In this context 'diversity' actually means 'people of a protected class'. I've seen people refer to a team of 10 African-American women as '100% diverse'.

"Diversity" is one of those terms that have diverged from its etymological roots. In modern American usage, an organization has diversity if it has lots of people who are diverse, and a person is diverse if they're black, Hispanic, or female. When someone wants to talk about other kinds of diversity, they'll say something like "let's find people who speak other languages" or "let's welcome people from nontraditional backgrounds" to avoid confusion.