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