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