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)(11,16)(12,15)(13,14)(17,18,22,23)(19,24,21,20)(26,30)(28,36)(31,33)(34,40)(3,8)(5,7)(10,13)(15,16)(18,23)(19,21)(25,26,29,30)(27,33,35,31)(28,37,36,32)(34,38,40,39)(9,11,14,12)(10,15,13,16)(17,19,22,21)(18,24,23,20)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(1,3)(2,5)(4,8)(6,7)(9,12,14,11)(10,16,13,15)(17,20,22,24)(18,19,23,21)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)(1,2)(3,5)(4,6)(7,8)(9,13,14,10)(11,16,12,15)(17,21,22,19)(18,24,23,20)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)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.