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