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