One vertex per element, one color per generator, with an edge from x to x·s.
(6,9)(7,11)(13,14,18,16)(15,20,17,19)(21,22)(23,27)(24,25)(26,28)(2,4)(5,6)(7,10)(8,9)(11,12)(14,16)(19,20)(22,25)(26,27) involution — undirected(1,2,3,4)(13,15,18,17)(14,19,16,20)(21,22)(23,26)(24,25)(27,28)(5,6)(7,10)(8,9)(11,12)(13,16,18,14)(15,20,17,19)(5,7,8,11)(6,10,9,12)(13,17,18,15)(14,20,16,19)(21,23,24,28)(22,26,25,27)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.