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