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