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