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