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