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