Currently there is no demo like that.
You can just install Sitecore Experience Accelerator (SXA) and create couple of simple pages with OOTB SXA components. More information here -> https://doc.sitecore.net/sitecore_experience_accelerator
As a second option - Sitecore Demo team is currently working on making Habitat Home deployable via two WDP packages. This will be basically what you want.
You can check it here https://experienceplatform.habitathomedemo.com. You can use that site for demonstration purposes for now but obviously just published content. You won't get access to sitecore editors.
Check https://github.com/Sitecore/Sitecore.HabitatHome.Content in upcoming weeks for some news.
Also check https://github.com/Sitecore/Sitecore.HabitatHome.Content/releases maybe it will be directly there.
Meanwhile follow readme of that github repository on how to install it via Visual Studio or follow Viet Hoang's awesome step by step guide on how to install it -> https://buoctrenmay.com/2018/08/01/sitecore-xp-9-0-2-and-sxa-1-7-1-demo-habitat-home-step-by-step-setup-guide/