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