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