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