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