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