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