I do not beleive there is an easy way, or even a way, to script out MPs.
They are stored in the MSDB so you may take a look at the associated MP tables and see if you can somehow export out the needed info.
I am sure there will also be columns that need to be addressed to make it work on another server (if this is your intention).
Most DBAs I know either recreate the MPs as needed OR, as many of my DBA colleagues do, forego maintenance plans and create your own home-grown maintenance plan scripts and jobs where you can add more detail, alerting and control.
Thanks
J. Kusch