In the Atahualpa Theme Options, click on the Post/Page Info Items button, then add
%edit('before', 'linktext', 'after')%
Prints a direct edit link for the post, IF the current viewer is permitted to edit posts, with linktext as the link text.
Example: %edit(' - ', 'Edit This Post', '')%
in the location you'd like the EDIT link. I tried it in the kicker and byline but if I stick it in the footer, after the date, it's far more discrete and doesn't ruin the look of my blog.