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