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