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