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