It is possible to copy a transaction and resend it - even if you're not the person who has created and sent it in the first place. This feature is to be found in your Overview, and by selecting the transaction you wish to copy you find a button called Copy Transaction.
When you copy an existing transaction and resend it, you will be the new sender of the transaction. Before it is sent, you can either edit the recipients, the signing method, the documents, etc. Or you can leave it exactly as it was sent in the first place.
Thus, when clicking Copy transaction you will be taken back to the “New Signing page” where the setup of the copied transaction is preset. Here, you can edit the parts you like before you resend it.