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