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