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