'05 W220 Fuse Diagram
I scanned and sent you the fuse diagram for my '05 W220; it's not an S55, but for most locations I believe it will suffice.
Fuse 13 is indeed for the driver's side power window, and it is in the fuse box just in front of the firewall on the driver's (left) side, in the engine compartment. The fuse slots are numbered on the panel, once you remove the cover.
pdf files of the 2005 W220 are attached below; because my diagram is badly wrinkled, and getting it to lay flat on the scanner was impossible, some areas are not optimally focused - but I hope it helps.
If you need one, also note that the chart has a part number. You should be able to order it through your dealer. For others who may need the '05 diagrams I will not be sending these out by email again - please download the pdf files.
PLEASE NOTE: Models of the W220 from 2003-2006 have FOUR fuse panels. In those models there are two in the engine compartment, one on each side; one under the right rear seat (access is via the panel surrounding the right rear courtesy light in the floor space); and one in the dashboard (right side for LHD cars, left side for RHD cars). It is easy to miss on the diagrams - Fuses 78 through 86 are in the dashboard fuse panel, which is particularly well-hidden. Check your owner's manual and the large "vehicle" diagram on the fuse chart for locations.
Also, there is a fuse box for a 150-amp fuse supplying power to the red wires for the SAM units; it is located in the right rear quarter panel, behind the trunk lining. And there is another in the right footwell. See post #8,
http://mbworld.org/forums/s-class-w220/348103-s430-issues-w220-2002-a.html for photos of each; also note the discussion in the thread. These are not the ordinary easy-to-replace fuses, and you will likely have to buy the whole box.