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