Diode direction for Door Pin Trigger
That diagram is not very useful, since all the switches depicted are in parallel, so you only need one connection, but if there were several lamps  to be lit separately e.g. in the trunk or under the hood, you'd need the diodes to prevent a single switch from pulling all the circuits on (low) at the same time. 

For that situation, the diodes as illustrated would be correct. The cathode, as Eugene points out, is the end with the stripe, and this is a negative side switch - the connection you are monitoring is held high by the bulb until a switch closes.