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