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