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