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