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