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