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