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)(11,18)(12,20)(13,15)(14,17)(16,22)(19,23)(21,24)(25,26,30,33)(27,31,34,38)(28,29,32,37)(35,36,39,40)(1,3,5,8)(2,6,4,7)(27,34)(31,38)(35,39)(36,40)(9,11,14,13)(10,15,17,18)(12,19,22,21)(16,23,20,24)(25,27,30,34)(26,31,33,38)(28,35,32,39)(29,36,37,40)(9,12)(10,16)(11,19)(13,21)(14,22)(15,23)(17,20)(18,24) involution — undirected(9,13,14,11)(10,15,17,18)(12,21,22,19)(16,23,20,24)(25,28)(26,29)(27,35)(30,32)(31,36)(33,37)(34,39)(38,40)(1,4,5,2)(3,7,8,6)(9,10)(11,15)(12,16)(13,18)(14,17)(19,23)(20,22)(21,24)(25,29)(26,32)(27,36)(28,33)(30,37)(31,39)(34,40)(35,38)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.