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