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