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