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