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