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