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