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