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