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