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