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