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