One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(9,10,17,32,13,20,31,39,16,23,14,21,15,22,29,34)(11,18,28,40,27,38,33,37,12,26,25,36,24,35,30,19)(2,4)(5,6)(7,8)(9,11,14,25,13,27,29,30,16,12,17,28,15,24,31,33)(10,18,21,36,20,38,34,19,23,26,32,40,22,35,39,37)(6,8)(9,12)(10,19)(11,16)(13,27)(14,30)(15,24)(17,33)(18,34)(20,36)(21,38)(22,40)(23,37)(25,29)(26,39)(28,31)(32,35) involution — undirected(2,4)(9,13,16,15)(10,20,23,22)(11,24,12,27)(14,29,17,31)(18,35,26,38)(19,36,37,40)(21,34,32,39)(25,33,28,30)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.