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