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