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