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