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