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