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)(11,17,19,24)(12,16)(13,15)(14,18,22,20)(21,23)(25,26,31,34,30,28,29,33)(27,35,36,40,37,32,38,39)(1,3,4,8)(2,5,6,7)(25,27,30,37)(26,32,28,35)(29,38,31,36)(33,40,34,39)(3,8)(5,7)(9,11)(10,14)(12,20)(13,19)(15,22)(16,24)(17,23)(18,21)(25,28,30,26)(27,32,37,35)(29,34,31,33)(36,39,38,40)(2,6)(5,7)(10,15)(14,22)(16,23)(17,24)(25,29,30,31)(26,33,28,34)(27,36,37,38)(32,39,35,40)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.