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