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