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