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