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