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