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