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