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