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)(11,15)(12,14)(13,16)(17,18)(19,28)(20,25)(21,22)(23,27)(24,29)(26,32)(30,31) involution — undirected(1,3,5,8)(2,6,7,4)(9,10,12,14)(11,13,16,15)(19,29)(20,31)(24,28)(25,30)(1,2)(3,6)(4,8)(5,7)(9,10)(11,13)(12,14)(15,16)(17,19,23,29)(18,24,27,28)(20,21,31,26)(22,25,32,30)(2,7)(3,8)(9,11)(10,13)(12,16)(14,15)(17,20,23,31)(18,25,27,30)(19,26,29,21)(22,28,32,24)(1,3)(2,4)(5,8)(6,7)(17,21,23,26)(18,22,27,32)(19,20,29,31)(24,30,28,25)(1,4)(2,3)(5,6)(7,8)(17,22)(18,26)(19,30)(20,28)(21,27)(23,32)(24,31)(25,29) 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.