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