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