dear Massino,
can you tell me the level of teaching? Then I will give you suggestions?
My advice is I have been presenting to professionals as well as academic, so you need simple slides with examples. Like introducing saas, paas and Iaas, introduce it as a layered model, and tell which companies provide the services like amazon for IaaS, Salesforce for SaaS and PaaS etc.
elucidate the distinction between these layers and how cloud provider use these layers to run their business. With these layers, they also add their own layers exspecially when dealing with SaaS like businessprocess as a service.
also include what are the main funtions of underline layers, you can also try to reference OSI model. At what level virtualization starts, network component interacts etc.
for security I can send you my paper a governance life cycle for pre to post adoption
if you have any questions do ask me
And I agree with aruna, Include NIST diagram for cloud computing