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