I would like to see the contact frame which i defined using contact pair. How can i visualize the contact frame?
You can visualize the contact (as a flat cylinder, orthogonal to the contact normal direction) as well as the contact force (as an arrow) and you can also split the contact force into normal and tangent. But the contact frame itself is not visualized automatically -- I have tried it and it clutters the scene. You could add custom mjvGeoms to mjvScene and visualize contact frames if you wish, but you have to write your own code to do that.