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