That is a little more complicated, but first thing, take a look at the webstorage object:
1) Try to successfully save something (a number) with webstorage
2) Try to fetch it (where your load function will be)
3) Having succeeded with the above, now for the actual game save; save every coordinate for every sprite - and all other variables (number of lives, level etc.) in webstorage. Then fetch as you did in step 2; and then have an "if game loaded" event in your game event sheet, that spawns and places everything.
At least, that's how I'd do it - but I'm unsure if this is the best way.
Far more simple would be for the save feature to only be available between playing levels (if your game features several levels); then you only need to store a few things; number of lives, the current level and the current score.