"地" is auxillary word. If "生动“ is followed by a verb, you should use "生动地“ For example： 他生动地讲述了事情的经过（ He told the story vividly） 他的讲述很生动（His narration is very vivid）

In general, 生動 is adj. 生動地 is adv.

“生动” means “vivid” and “生动地” means “vividly”.Generally speaking，“生动地” is not pulled at the end of the sentence.In a way，“生动” is equal to “生动的”.

It seems like you append a 'ly' behind an adjective to make it to an adverb. Just like 'vivid(生动)' and 'vividly(生动地)'