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