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