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