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