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