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