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)(27,38)(28,34)(29,40)(30,36)(31,37)(32,35)(33,39)(9,11,14,20)(10,15,17,18)(12,19,13,22)(16,23,21,24)(25,27,31,39)(26,33,37,38)(28,29,36,32)(30,40,34,35)(2,5)(6,8)(25,28,32,27,31,36,29,39)(26,34,35,38,37,30,40,33)(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)(26,35,37,40)(27,36,39,28)(30,38,34,33)(9,13,14,12)(10,16,17,21)(11,19,20,22)(15,24,18,23)(25,30,32,33,31,34,29,38)(26,36,35,39,37,28,40,27)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.