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