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