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)(11,13)(12,20)(14,16)(15,18)(17,23)(19,24)(21,22)(29,37)(32,36)(34,40)(38,39)(1,2,4,6)(3,7,8,5)(9,11,14,18)(10,15,16,13)(12,21,23,19)(17,22,20,24)(25,26,30,28)(27,33,35,31)(29,32,37,36)(34,39,40,38)(1,2)(3,5)(4,6)(7,8)(10,16)(11,18)(17,20)(19,21)(25,27,30,35)(26,31,28,33)(29,34,37,40)(32,38,36,39)(1,3)(2,5)(4,8)(6,7)(9,12,14,23)(10,17,16,20)(11,19,18,21)(13,22,15,24)(9,10)(11,15)(12,17)(13,18)(14,16)(19,24)(20,23)(21,22)(25,28,30,26)(27,31,35,33)(29,36,37,32)(34,38,40,39)(9,13,14,15)(10,18,16,11)(12,22,23,24)(17,21,20,19)(25,29)(26,32)(27,34)(28,36)(30,37)(31,38)(33,39)(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.