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