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