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