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