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