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