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