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