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