here you have a stacked bar chart draft for Excel: http://www.office-loesung.de/ftopic210491_0_0_asc.php (german excel forum, at the end of the website you can download it and also see a screenshot)
Either convert your hypnogram to EDF format or make an EDF hypnogram using our software Polyman at http://www.edfplus.info/downloads/software/polyman.zip. The same program then nicely displays the hypnogram.