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