WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Hazard Warning Switch Components (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Fig 2: Identifying Hazard Warning Switch Components (2 Of 2)