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