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