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