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