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