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