One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,9)(10,12)(13,14,18,16)(15,20,17,19)(21,22)(23,26)(24,25)(27,28)(2,4)(6,9)(10,11)(13,15)(14,19)(16,20)(17,18)(21,22,24,25)(23,26,28,27)(1,2,3,4)(6,9)(10,11)(15,17)(19,20)(22,25)(26,27)(5,7,8,12)(6,10,9,11)(13,16,18,14)(15,19,17,20)(21,23,24,28)(22,26,25,27)(5,6)(7,11)(8,9)(10,12)(13,17,18,15)(14,20,16,19)(21,22)(23,27)(24,25)(26,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.