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