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