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