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)(14,25)(19,27)(22,28)(24,31)(26,30)(29,33)(32,35)(34,36) involution — undirected(5,7)(6,12,16,28)(8,19)(9,20)(10,22)(11,21)(13,15,18,17)(14,27,31,36)(23,29,30,32)(24,33)(25,35)(26,34)(5,7)(6,13,16,18)(8,19)(9,20)(10,22)(11,21)(12,17,28,15)(14,29,31,32)(23,36,30,27)(24,33)(25,35)(26,34)(2,4)(5,8,9,24,11,26,10,25)(6,14,15,30,16,31,17,23)(7,19,20,33,21,34,22,35)(12,27,18,32,28,36,13,29)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.