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