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