From Stuttgart Airport (STR) it is only a 16 minutes train ride to the conference venue.
When you arrive at the airport, leave the baggage claim area towards the train station (S-Bahn).
Before using the stairs/escalator down to the platform, use one of the blue/red/grey ticket vending machines (Fahrkarten/Tickets) to get a ticket for public transport. To get to the conference venue, enter Stuttgart Universität as destination (2 zones, € 2.60 adults), and take any train (S2 or S3) that runs towards city center (Stadtmitte/Innenstadt) and main station (Hauptbahnhof).
Normally, these trains run from platform 2. During normal hours (05:08 to 22:08) there is a train at least every 20 minutes (minutes :08, :18, :38, and :48).
Get off the train at the stop Stuttgart Universität (University) and use the exit Universitätszentrum. From there the way to building is sign posted or have a look at the map. You can also take a taxi (about € 31.00, depending on time of day, traffic situation, and duration of the trip), but it is likely that public transport is faster.