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