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