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