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