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