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