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