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