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