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