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