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