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