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