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