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