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