This is the best version I could find so if you come across something better leave a comment and let me know.
Here are the lyrics I found here
Kiyoshi kono yoru hoshi wa hikari
sukui no miko wa mabune no naka ni
nemuri tamo-o. itoyasuku.
Kiyoshi kono yoru mitsuge ukeshi
makibitotachi wa miko no mimae ni
nukazukinu, kashikomite.
A nice-sounding version of きよしこのよる with a third verse is used in this AMV, and an instrumental version that displays the written lyrics for the first and third verse can be found here.