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