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