Let's take a sample graph and look at it.
plot(G, 'XData', V10(:, 1), 'YData', V10(:, 2), 'ZData', V10(:, 3));
Look at the Nodes table of the graph G.
If that table had a variable Name, those would be the names of the nodes. [See the Add Node Names section on this documentation page.] If it did you could modify one element of that variable to change the name of one node. In this case since it doesn't have that variable you can add it to the table. G2.Nodes.Name = ["alpha"; "beta"; "gamma"; "delta"; "epsilon"; ...
"zeta"; "eta"; "theta"; "iota"; "kappa"];
plot(G2, 'XData', V10(:, 1), 'YData', V10(:, 2), 'ZData', V10(:, 3));
G2.Nodes
ans =
Name
___________
{'alpha' }
{'beta' }
{'gamma' }
{'delta' }
{'epsilon'}
{'zeta' }
{'eta' }
{'theta' }
{'iota' }
{'kappa' }
Or if you just wanted to change the labels in the plot, use labelnode.