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