The way to play hex on a square go like board is to have a go board with a line running through SW to NE diagonals of each square of the board representing that path of diagonal connectivity. So all directions of connectivity would be shown by lines on the board. Unlike in a go board where the diagonal connectivity of cells is not marked by lines. Playing big board hex is better on a square board because of spatial efficiency of square compared to diamond shape board.
If you use the design scheme button you will find a board with pieces on intersections, so that would have the lines marking connectivity. But unfortunately for you it's diamond shaped... If you have any graphic design skills you could probably make the image and get it added in with the other schemes.
@kocbftn, @fastplayer, there are a few "design schemes" available for hex in the site. I'm not sure I understand the suggestion here.
One of the schemes is a parallelogram board with diagonals (in one diagonal direction). How does the suggestion here would differ from that - to look more square shape than diamond shape it looks like now?