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)(27,33)(28,30)(29,32)(31,35)(34,39)(36,40)(37,38) involution — undirected(1,2)(3,6)(4,7)(5,8)(10,15)(11,20)(17,22)(18,21)(25,27,31,29)(26,32,35,33)(28,36,39,38)(30,37,34,40)(1,3)(2,5)(4,8)(6,7)(10,15)(11,20)(17,22)(18,21)(25,27,31,29)(26,33,35,32)(28,38,39,36)(30,37,34,40)(3,8)(5,6)(9,11)(10,16)(12,21)(13,22)(14,20)(15,19)(17,24)(18,23)(25,28,31,39)(26,34,35,30)(27,36,29,38)(32,40,33,37)(1,2)(3,5)(4,7)(6,8)(9,12,14,23)(10,17,15,22)(11,21,20,18)(13,16,24,19)(25,29,31,27)(26,32,35,33)(28,38,39,36)(30,37,34,40)(1,3)(2,6)(4,8)(5,7)(9,13,14,24)(10,18,15,21)(11,17,20,22)(12,19,23,16)(25,30,31,34)(26,28,35,39)(27,37,29,40)(32,36,33,38)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.