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