Unfortunately, it’s difficult to find a good shot of the docking adapters in nomal docking videos. Scott Manley has a bunch of good shots in this video, and I found this fantastic video showing the docking process in detail.
Or read the wiki on the International Docking System (IDS), or spacecraft docking systems in general.
Unfortunately, the IDS isn’t androgynous right now, the passive and active sides are slightly different. Androgyny is planned for a future version.
A lot of people are afraid of non-standard letters.