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