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