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