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