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