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