A major difficulty in enterprise computing is the modeling of complex application topologies consisting of numerous individual components and their relationships. Especially in the context of cloud computing, the Topology and Orchestration Specification for Cloud Applications (TOSCA) has been proposed recently for standardization to tackle this issue. However, TOSCA currently lacks a well-defined visual notation enabling effective and efficient communication in order to transport the semantics of the encoded information to human beings. In this paper, we propose a visual notation for TOSCA based on established usability research which provides additional concepts for visual modularization and abstraction of large application topologies.