[Context and motivation] Self-adaptive systems (SAS) monitor and adapt to changing end-user requirements, operating context conditions, and resource availability. Specifying requirements for such dynamic systems is not trivial. Most of the research on self-adaptive systems (SAS) focuses on finding solutions to the requirements that SAS is built for. However, elicitation and representation of requirements for SAS has received less attention at early stages of requirements engineering (RE). [Question/problem] How to represent requirements for SAS in a way which can be read by non-engineering stakeholders? [Principal ideas/results] A requirements modeling language with a diagrammatic syntax to be used to elicit and represent requirements for SAS and perform analysis based on our recently proposed core ontology to perform RE for SAS. [Contribution] A modeling language, called Adaptive RML, for the representation of early requirements for Self-adaptive systems (SAS). The language has graphical primitives in line with classical goal modeling languages and is formalized via a mapping to Techne. Early validation is performed by modeling the same case study in an established goal modeling language and in Adaptive RML. The results suggest that context and resource concepts, as well as relegation and influence relations should be part of graphical modeling languages used to make early requirements models for SAS and to perform analysis over them.