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