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