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