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