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