Answer:
The conclusion is invalid.
The required diagram is shown below:
Explanation:
Consider the provided statement.
Great tennis players use Hexrackets. Therefore, if you use a Hexracket, you are a great tennis player.
From the above statement we can concluded that Great tennis players use Hexrackets. But it may be possible that some people who use a haxracket are not great tennis player.
Therefore, the conclusion is invalid.
The required diagram is shown below: