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