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