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