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