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