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