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