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