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