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