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