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