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