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