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