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