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