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