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