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)(11,16)(12,20)(13,18)(14,15)(17,22)(19,21)(23,24)(28,36)(31,38)(34,40)(37,39)(1,3,5,8)(2,6,4,7)(25,26)(27,32)(28,31)(29,33)(30,35)(34,39)(36,38)(37,40)(1,2,5,4)(3,6,8,7)(10,15)(11,18)(17,20)(19,24)(25,27)(26,30)(28,34)(29,35)(31,37)(32,33)(36,40)(38,39)(1,2,5,4)(3,6,8,7)(9,11,14,18)(10,16,15,13)(12,19,22,24)(17,23,20,21)(25,28,29,36)(26,31,33,38)(27,34,35,40)(30,37,32,39)(1,4,5,2)(3,7,8,6)(9,12,14,22)(10,17,15,20)(11,19,18,24)(13,21,16,23)(25,27)(26,32)(28,34)(29,35)(30,33)(31,39)(36,40)(37,38)(9,13,14,16)(10,18,15,11)(12,21,22,23)(17,24,20,19)(25,26)(27,30)(28,31)(29,33)(32,35)(34,37)(36,38)(39,40)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.