One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,15)(12,14)(13,16)(17,18)(19,26)(20,23)(21,31)(22,25)(24,30)(27,32)(28,29) involution — undirected(2,5)(6,8)(9,11)(10,13)(12,16)(14,15)(17,19,22,30)(18,24,25,26)(20,28,31,27)(21,29,23,32)(10,14)(11,16)(17,20)(18,21)(19,27)(22,31)(23,25)(24,32)(26,29)(28,30) involution — undirected(1,3,4,7)(2,6,5,8)(10,14)(13,15)(17,18)(19,28)(20,21)(22,25)(23,31)(24,32)(26,29)(27,30)(2,5)(6,8)(10,14)(13,15)(17,21,22,23)(18,20,25,31)(19,29,30,32)(24,28,26,27)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.