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