Here is a simple diagram and explanation of the structure of a cell as found in the Class 9 Science NCERT book (Chapter 5: The Fundamental Unit of Life):

Structure of a Cell (Class 9)

A typical cell (especially a plant cell) contains the following main parts:

1. Cell Wall (only in plant cells):

   • Outermost rigid layer, gives shape and protection.

2. Cell Membrane (Plasma Membrane):

   • Thin, flexible boundary inside the cell wall (in plants) or outermost layer (in animals). Controls movement of substances in and out

3. Cytoplasm:

   • Jelly-like substance inside the cell where all organelles are suspended

4. Nucleus:

   • Spherical structure, usually in the center. Contains genetic material (DNA), controls cell activities

5. Cell Organelles:

   • Mitochondria: "Powerhouse" of the cell, produces energy.

   • Endoplasmic Reticulum (ER): Network for transport within the cell.

   • Golgi Apparatus: Packages and distributes materials.

   • Ribosomes: Make proteins.

   • Plastids: (only in plant cells, e.g., chloroplasts for photosynthesis)

   • Vacuole: Storage sac (large in plant cells).

   • For a clear, colored diagram:

     • Refer to your NCERT Class 9 Science book, Chapter 5, Figure 5.2

     • You can also find a well-labeled diagram in most Class 9 Science textbooks and revision notes
       
       
       In summary:
       A cell has a cell wall (plant), cell membrane, cytoplasm, nucleus, and several organelles like mitochondria, ER, Golgi, ribosomes, vacuole, and plastids.
       Draw and label these parts for your exam.

As the diagram picture is not given above you can see it in your textbook or search on the basis of above information given to you,if it still doesnt clear your doubt you can ask again.