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