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