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