If you want to delete a report (automated or draft), simply hover your mouse over the relevant report in your home screen, and select Remove.
Note: When you want to delete an automated report, you are presented with two options:
Delete report (this will delete this one report, but will leave the rest of the reports in the automation cycle. It means your next monthly report will still be sent, although you deleted the report for this month).
Cancel automation (this will delete the report and cancel all future reports).