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