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