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