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