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