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