There is no option for that.
The PDF invoice plugin can potentially be modified to send an invoice in PDF in that email notification :
www.hikashop.com/en/component/hikashop/product/cid-18.html
However, note that the PDF invoice has it's own view which is different from the view for the invoice that you can get when you click on the invoice button of the order on the backend. So if you customized that view, you won't see the change in the PDF invoice that can be attached to the notification by the plugin and you would have to reapply your customizations.