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