One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,8)(6,7)(9,10)(11,16)(12,15)(13,14)(19,25)(20,27)(23,29)(24,28) involution — undirected(1,3,6,5)(2,4,7,8)(9,11,14,12)(10,15,13,16)(17,18)(19,23)(20,24)(21,22)(25,29)(26,30)(27,28)(31,32)(2,7)(4,8)(9,10,14,13)(11,15,12,16)(18,22)(23,29)(24,28)(30,32)(17,19)(18,23)(20,26)(21,25)(22,29)(24,30)(27,31)(28,32) involution — undirected(1,4,6,8)(2,3,7,5)(9,12,14,11)(10,15,13,16)(17,18)(19,23)(20,28)(21,22)(24,27)(25,29)(26,32)(30,31)(1,5,6,3)(2,4,7,8)(9,13,14,10)(11,16,12,15)(17,20)(18,24)(19,26)(21,27)(22,28)(23,30)(25,31)(29,32)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.