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