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