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