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