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