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