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)(11,15)(12,22)(13,17)(14,18)(16,19)(20,24)(21,23)(25,26,31,34)(27,32,29,28)(30,33,39,38)(35,40,37,36)(1,3,5,8)(2,6,7,4)(9,11,16,14)(10,15,19,18)(12,21,13,20)(17,24,22,23)(25,27,31,29)(26,28,34,32)(30,35,39,37)(33,36,38,40)(1,3)(2,4)(5,8)(6,7)(9,12,16,13)(10,17,19,22)(11,20,14,21)(15,23,18,24)(25,28,31,32)(26,27,34,29)(30,36,39,40)(33,35,38,37)(1,4)(2,3)(5,6)(7,8)(9,13,16,12)(10,17,19,22)(11,21,14,20)(15,23,18,24)(25,26)(27,28)(29,32)(30,38)(31,34)(33,39)(35,40)(36,37)(9,14,16,11)(10,18,19,15)(12,21,13,20)(17,24,22,23)(25,29,31,27)(26,32,34,28)(30,37,39,35)(33,40,38,36)(9,15,16,18)(10,11,19,14)(12,23,13,24)(17,20,22,21)(25,30,31,39)(26,33,34,38)(27,35,29,37)(28,36,32,40)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.