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