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