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