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