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