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