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