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