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