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