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