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