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