There are a few options:
The links above are for pre-configured and available SmartConnectors that you can use to read SAP audit logs and have them parsed and passed to Logger or ESM / Express. Please note that these are audit logs only so it won't give you detailed logs in how the SAP system operates itself.
I would encourage you to read the following post that I made a year ago:
SAP is NOT simple in any stretch, so please do check option around this. I would encourage you to take a look at Agile-SI though, this is a great piece of middleware that will add a lot of intelligence to the SAP log creation / integration.