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