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