Auto Transformer Starter Panel

The basic, motor start with several voltage tap till reach at its rate.

see below wiring

A basic autotransformer starter doesn't have the contactor on the star point of the transformer, just a shorting link. The basic starter is open transition at change over.

Your drawing is of a Korndorfer starter. Which is closed transition at change over giving a smoother start.

For the sequence of operation check here http://en.wikipedia.org/wiki/Korndorfer_starter#Motor_stationary

how about capacity transformer i have to use?

and what about control diagram?

may i know the complete diagram?

You asked "How to design Auto transformer starter Panel", not would we design it!

I'm sure someone would do it for a fee!

Just about every major motor control manufacturer provides power and control wiring diagrams for the Autotransformer Starters that they sell already made. If you don't know how to do it (as evidenced by your question in the first place), an easier route to success would be to buy one from one of these suppliers. You will have to buy the components from them anyway...

But if your foolhardiness out shines your common sense and you want to do it yourself anyway, get hold of a catalog from your favorite supplier and read it. Siemens, ABB, Schneider, GE, Allen Bradley, they all show their diagrams right in the catalogs.