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