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