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