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)(11,21)(12,26)(13,19)(14,18)(15,20)(16,23)(17,27)(22,33)(24,32)(25,31)(28,35)(29,34)(30,39)(36,37)(38,40)(1,3,5,4)(2,6,7,8)(9,11)(10,16,20,32)(12,22)(13,23)(14,24)(15,25)(17,33,35,30)(18,21,19,31)(26,40,34,36)(27,37)(28,38)(29,39)(2,7)(6,8)(9,12,15,29)(10,17,20,35)(11,22,25,39)(13,27,14,28)(16,30,32,33)(18,26,19,34)(21,36,31,40)(23,37,24,38)(1,4,5,3)(2,8,7,6)(12,27)(13,14)(17,26)(18,19)(21,31)(22,37)(23,24)(28,29)(30,36)(33,40)(34,35)(38,39)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.