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