If you are using content from these stories in your work, you can cite them as follows (or equivalent depending on your citation system):
British Muslim Heritage Centre, ‘Title of the story’, Stories of Sacrifice Exhibition website (2016), [accessed date].

For example:
British Muslim Heritage Centre, ‘Profile: Ahmad Khan’, Stories of Sacrifice Exhibition website (2016), < http://www.storiesofsacrifice.org.uk/exhibition/burials/> [accessed 20 January 2016].