Here we clearly see the hexagonal structure of the Discovery One spacecraft from 2001: A Space Odyssey. The engine housings as well as the connective structure between the engines and the habitation spheroid have an overtly hexagonal form to them.
In this screenshot of the Treaty of Armens from the TNG episode The Ensigns of Command, we see the Sheliak version of the treaty alongside the "English" (or if you will "Federation Standard") version. Note that the Sheliak, who apparently consider themselves intellectually superior to humanoids, seem to have developed some sort of flowing-hexagon-based communication system. This is probably why they consider themselves superior. If the settlers of Tau Cygna V had developed a similarly hexagonal way of life, one can only imagine how things could've worked out differently for them.
This is a screenshot of media owned by Paramount Pictures, and its use here constitutes fair use under United States copyright law. As I see it. FTVW.