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