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