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