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