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