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