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