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