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