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