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