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