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