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