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