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