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