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