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