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