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