How to program this bending tool?

i have a bending tool with 3 pistons.cylinder 1 with 2 sensors S3 and S4.cylinder 2 with 2 sensors s5 and s6,cylinder 3 with s7 and s8. The initial condition for the machine to start is that all the piston must be retracted that is piston 1 must be in s3,piston 2 in s5 and piston 3 in s7.The outputs are electromagnetic valves Y1,Y2,Y3,Y4,Y6.When pressing start,the EM valve Y2 is on and the piston 1 extends.when reaching s4,Y2 is shut down and Y3 is switch on and piston 2 extends.when reaching s6,Y3 is shut down and after 2 seconds Y4 is switched on and piston 2 retracts.on reaching s5 ,valve Y4 shut down,valve Y5 is switch on and piston 3 extends.on reaching s8,valve Y5 is shut down and after 2 seconds valve Y6 is switch on and piston 3 retracts.on reaching s7, valve y6 is shut down and after 2 seconds,valve Y1 is on and piston 1 retracts.Reaching s3,piston 1 retracted,valve y1 is shut down and the device has reached its starting positon again. start button must be pressed again.

Can anyone help me to write its program on siemens s7 300 please?