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