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