One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,15)(8,17)(9,13)(10,19)(11,14)(12,16)(18,20)(21,22)(23,28)(24,32)(25,29)(26,31)(27,30)(33,34)(35,36) involution — undirected(1,2,4,3)(5,7,9,16)(6,12,13,15)(8,11,18,10)(14,17,19,20)(21,23)(22,28)(24,29)(25,32)(26,36)(27,33)(30,34)(31,35)(5,8,10,16,9,18,11,7)(6,12,14,17,13,15,19,20)(21,24,25,34,27,35,26,28)(22,23,31,36,30,33,29,32)(1,3,4,2)(6,13)(12,15)(14,19)(17,20)(21,25,27,26)(22,29,30,31)(23,32,33,36)(24,34,35,28)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.