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