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