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