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