Reach out to communities like Women Who Code, Lesbians in Tech, and Code2040. Work with them. Pay them.
Then go out and find people whose work impresses you on the web. Email them directly.
Make sure you're not hiring for "culture fit". Instead, ask: how will this candidate provide a new perspective?
And make sure your culture isn't accidentally a dude's club. What are you doing to promote inclusivity and empathy? How are you avoiding baking common biases into your culture? Who gets to set process? How is success measured?