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