class SRE implements DevOps ... ohh yeahhh
This exam is not for the faint for heart. Think stackdriver on crack. But you want to be an SRE so no problem 
Please note if you don't know anything about SRE practices and DevOps tool and Stackdriver in Google Cloud don't look at the sheet yet. I recommend this prep sheet only after you know something and before you are ready to take the exam. This sheet helps you to focus because this area is vast (no knowledge overload) to bring you up to exam readiness.