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