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