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)(11,19)(12,22)(13,18)(14,16)(15,21)(17,23)(20,24)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,38)(37,40)(1,2)(3,6)(4,7)(5,8)(9,11,14,21)(10,15,16,19)(12,20,23,13)(17,24,22,18)(25,26)(27,30)(28,31)(29,32)(33,35)(34,38)(36,39)(37,40)(1,3,5,4)(2,6,8,7)(10,16)(15,19)(17,22)(18,24)(25,26,29,32)(27,30,35,33)(28,31,37,40)(34,38,36,39)(1,4,5,3)(2,7,8,6)(9,10)(11,15)(12,17)(13,18)(14,16)(19,21)(20,24)(22,23)(25,26)(27,30)(28,31)(29,32)(33,35)(34,38)(36,39)(37,40)(9,12)(10,17)(11,20)(13,21)(14,23)(15,24)(16,22)(18,19)(25,27)(26,30)(28,36)(29,35)(31,39)(32,33)(34,37)(38,40) involution — undirected(9,13,14,20)(10,18,16,24)(11,12,21,23)(15,17,19,22)(25,28,29,37)(26,31,32,40)(27,34,35,36)(30,38,33,39)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.