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