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