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