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