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