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