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