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