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