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