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