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