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