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