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