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