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