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