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