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