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