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