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