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