Just go to http://we.tl/rj8JJSmoKW
Use the link http://dx.doi.org/10.17952/24APS.2015 for the whole book or http://dx.doi.org/10.17952/24APS.2015.001 for a paper on a page 1 (George Barany's award article). For your paper use different page number, of course.
By the way, proceedings of 23rd APS are now indexed as well - you can see them at http://dx.doi.org/10.17952/23APS.2013.xxx where xxx is the page number in the proceedings book (clicking on this link will bring you Jimmy Tam's paper on page 001. Deleting the last three digits from the link will bring you the whole proceedings book.)
From the survey performed last year, an overwhelming majority of participants (over 90% of respondents) asked for availability of all materials presented at the symposium in pdf form. Participants had an option to submit their poster or lecture file in powerpoint or pdf format. We took a picture of each poster and compiled all materials (our pictures and author's submissions) into a large pdf. If you are interested in these materials, let us know.