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