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