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