We have added a feature on s2survey.net that will allow for a high resolution download of each the chart. Move the mouse cursor over the chart, and a download-symbol will appear on the upper right.
If the screenshot-resolution if sufficient, a right click on the chart should also allow for a download.
Please note, that the charts in the online descriptives are limited. So, if you need a cusstomized chart, just copy and paste the table with the data to Excel or LibreOffice Calc, and quickly create you custom chart based on these values.