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