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