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