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