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