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