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