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