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