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