Overview:

Use FL1 train to Fiera di Roma, or bus/taxi/car; free shuttles run event days between central Rome and Fiera Roma.

Details:

Event shuttles: 08:00-18:00 on show days (Tue-Thu) between central Rome ⇄ Fiera Roma; check the SiGMA App for route & stop details.
Public transport (Fiera Roma): FL1 train; ATAC 808/089/701/701L; Cotral.
Airport to venue: FCO → Fiera Roma ~10 min by taxi (traffic-dependent).

Source: Agenda