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