The colored bars are to represent the spectrum of different neurotypes and gender identities that neurodivergent individuals have. The infinity symbol is to represent neurodiversity.
Neurogender is an umbrella term to describe when someone's gender is somehow linked to their neurotype, mental illness, or neurological conditions. There are many different neurogenders related to most, if not all, neurodivergencies. Not everyone who is neurodivergent has a neurogender, but each neurogender is exclusive to certain neurotypes. Oftentimes there are similar terms available to neurotypicals who have similar experiences and don't wish to appropriate.