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