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