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