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