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)(11,15)(12,14)(13,16)(17,18)(19,23)(20,22)(21,24)(25,26,29,30)(27,33,34,31)(28,36,37,32)(35,38,40,39)(9,11,12,16)(10,13,14,15)(17,18)(19,23)(20,22)(21,24)(26,30)(27,34)(28,37)(38,39)(10,14)(13,15)(17,18,20,22)(19,21,24,23)(25,26)(27,31)(28,36)(29,30)(32,37)(33,34)(35,39)(38,40)(1,2)(3,5)(4,6)(7,8)(9,11)(10,15)(12,16)(13,14)(17,18)(19,21)(20,22)(23,24)(25,27,29,34)(26,31,30,33)(28,35,37,40)(32,38,36,39)(1,3,4,7)(2,5,6,8)(9,10)(11,15)(12,14)(13,16)(17,19,20,24)(18,21,22,23)(25,28,29,37)(26,32,30,36)(27,35,34,40)(31,38,33,39)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.