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