If you mean the wireframe-like gizmo for the CharacterController, you can select the CharacterController game object and in the Game view turn on the toggle button called "Gizmos". The gizmo for the CharacterController will then be drawn in the Game View (but only in the editor; not when you build the game).

If by character controller you mean the capsule which comes with the First Person Controller, that would be the "Graphics" child of the First Person Controller prefab. Simply turn on the Mesh Renderer of the "Graphics" game object and it will display in game mode. However, if you use the First Person Controller just like it is provided with your unity install without modifying it, you won't see it in the first person perspective unless you look into a mirror surface. The camera is attached to the top so that the capsule is not visible by rotating the camera.