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