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