In the absence of real-life role models, women scientists portrayed in the media enable young women to imagine themselves as future scientists. Both traditional media and social media have the potential to provide role models, but their representations of scientists reinforce, rather than challenge, long-standing gendered stereotypes. Women Doing Science, a social media effort, was founded by the authors to address this representation gap by sharing daily photos of diverse women in science, technology, engineering, and math (STEM) with accompanying research descriptions in English and in other languages. To date, Women Doing Science has highlighted over 800 scientists to an audience of ~100,000 followers from around the world, who are primarily women in undergraduate and graduate STEM degree programs. Here, we evaluate the success of the Women Doing Science Instagram page in portraying women scientists with diverse racial and national identities. Furthermore, we explore which aspects of posts drive higher engagement from the audience. We find that our Instagram audience has higher engagement with posts featuring Women of Color, multiple languages, and posts that challenge stereotypes associated with women in STEM. In addition, we find that Women of Color are more likely to include additional aspects of their identity in their biographies, and that a primary reason our audience follows the page is because of the diversity portrayed in the posts. These results imply the powerful potential for social media platforms like Instagram to source diverse role models that expand conventional images of STEM professionals and allow international audiences to develop their STEM identities.