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