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)(25,26,31,30)(27,32,36,40)(28,33,39,38)(29,37,35,34)(9,11,14,20)(10,15,17,18)(12,19,13,22)(16,23,21,24)(25,27,31,36)(26,32,30,40)(28,37,39,34)(29,33,35,38)(2,5)(6,8)(25,28,31,39)(26,33,30,38)(27,35,36,29)(32,34,40,37)(1,3,4,7)(2,6,5,8)(9,12,14,13)(10,16,17,21)(11,19,20,22)(15,23,18,24)(25,26,31,30)(27,32,36,40)(28,38,39,33)(29,34,35,37)(9,13,14,12)(10,16,17,21)(11,19,20,22)(15,24,18,23)(25,29,31,35)(26,34,30,37)(27,28,36,39)(32,38,40,33)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.