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