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