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)(27,33)(28,38)(29,39)(30,32)(31,36)(34,35)(37,40)(2,5)(6,7)(9,11,13,12)(10,14,16,15)(17,19,20,23)(18,21,22,24)(25,27,35,28,30,37,29,36)(26,31,39,40,32,38,34,33)(1,3,4,8)(2,6,5,7)(9,11,13,12)(10,15,16,14)(19,23)(21,24)(26,32)(27,28)(29,35)(31,33)(36,37)(38,40)(3,8)(6,7)(9,12,13,11)(10,15,16,14)(25,28,29,27,30,36,35,37)(26,33,34,38,32,40,39,31)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.