Sitemapper has not been updated for direct uploading to S-Drive.  Not to worry though, we are working on this now and hope to have that addressed later this year.  To place your sitemap within any S-Drive account, you simply need to upload all the files Sitemapper exported with our Direct or Free FTP program.  Just connect to S-Drive and place the sitemap.xml file inside of your sites folder and you are ready to go!