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