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