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