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