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